CVE-2026-2790

HIGH 8.8

Same-origin policy bypass in the Networking: JAR component

CVSS Score

8.8

EPSS Score

0.0%

EPSS Percentile

0th

Same-origin policy bypass in the Networking: JAR component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Vendor	mozilla
Product	firefox
Ecosystems	Browser JavaScript
Industries	Technology
Published	Feb 24, 2026
Last Updated	Apr 13, 2026

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Affected Versions

Mozilla / Firefox

All versions affected

Mozilla / Thunderbird

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=2008426 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-13/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-15/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-16/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-17/

Credits

Surya Dev Singh